Calcium acetate Sodium benzoate CH2—CH2—C—OK Br Br Pottasuim2,3-Dibromo propanoate O Physical Properties Carboxylic acid molecule is polar and can form hydrogen bonds with each other and with other kinds of molecules. The aliphatic acid with 4 or lees Catoms are miscible with water A 5 C party soluble and the higher are Insoluble. Carboxylic acids are soluble In non polar or lees polar solvents like Ether Alcohol , Benzene. These very high Boiling points are due to the fact that the pair of carboxylic acid molecules are held together by two hydrogen bonds O:\\\\\\\\\\\\\\\\\H—O R—C C—R O—H \\\\\\\\\\\\\\\:O The odors of lower aliphatic acid sharp and higher acid have little odor because of their low volatility. SALTS OF CARB. ACIDS RCOOH + NaOH In soluble in water R—C—ONa + H2O O soluble in water The interconversion of acid and their salts may be used in two important ways: (1)Identificatio (2) September We can separate the acid from non-acid compounds by taking advantage of its solubility and their insolubility in aqueous base. Preparation of CARB. Acid 1) Oxidation of primary alcohols H+ RCOOH Insol in water KMnO4 + R—CH2—CH R—C—OK + MnO2 + KOH Purple solublein water acid or base واحيانا نستخدمK2Cr2O7 وKMnO4 CH3 CH3 O CH3—CH—CH2OH KMnO4 CH3—CH—C—OH Butyric acid 2)Oxidation of alkyl benzene O Ar—R KMnO4 K2Cr2O 7 والعوامل المؤكسدة Ar—C—OH NO2 P—N.bezoic acid O2N CH3 K2Cr2o7 H2SO4 heat COOH The side chain is oxidized down to the ring only a carboxyl group remaining to indicate the position of the original side chain.